export default {
  //为当前口快开启命名空间
  namespaced:true,
  // 模块的state数据
  
  state:()=>({
     // 购物车的数组，用来存储购物车中每个商品的信息对象
     // 每个商品的信息对象，都包含如下 6 个属性：
     // { goods_id, goods_name, goods_price, goods_count, goods_small_logo, goods_state }
    cart: JSON.parse(uni.getStorageSync('cart')||'[]')
  }),
  
  mutations:{
    addToCart(state,goods ){
     const findResult= state.cart.find(x=>x.goods_id===goods.goods_id)
     // console.log(findResult)
     if(!findResult){
       state.cart.push(goods)
     }
     else{
       findResult.goods_count ++
     }
     // console.log(state.cart)
     this.commit('m_cart/saveToStorage')
    },
    saveToStorage(state){
      uni.setStorageSync('cart',JSON.stringify(state.cart))
    },
    changeGoodsState(state,goods){
      const findResult = state.cart.find(x=>x.goods_id === goods.goods_id)
      if(findResult){
        findResult.goods_state = goods.goods_state
        this.commit('m_cart/saveToStorage') 
      } 
    },
    updateGoodsCount(state,goods){
     const findResult = state.cart.find(x=>x.goods_id === goods.goods_id)
     if(findResult){
       findResult.goods_count=goods.goods_count
       this.commit('m_cart/saveToStorage')
      }
     },
     removeGoodsById(state,goods_id){
       state.cart= state.cart.filter(x=>x.goods_id !== goods_id)
       this.commit('m_cart/saveToStorage')
     },
     updateAllGoodsState(state,newState){
       state.cart.forEach(x=>x.goods_state = newState)
       this.commit('m_cart/saveToStorage')
     }

  },
  getters:{
    total(state){
      // let c=0
      // state.cart.forEach(x=> c+= x.goods_count)
      // return c
      
     return state.cart.reduce((total,item)=> total += item.goods_count,0)      
    },
    checkedCount(state){
      return state.cart.filter(x=>x.goods_state).reduce((total,item)=>{ return total += item.goods_count},0)
    },
    // 计算选中商品的总价
    checkGoodsAmount(state){
      return state.cart.filter(x=>x.goods_state)
                       .reduce((total,item)=> total += item.goods_count * item.goods_price,0)
                       .toFixed(2)
    }
  }
}